Magnetic disk drives are used to store and retrieve data in many electronic devices including computers, televisions, video recorders, servers, digital recorders, etc. A typical magnetic disk drive includes a head having a slider and a transducer with a read and write element that is in very close proximity to a surface of a rotatable magnetic disk. As the magnetic disk rotates beneath the head, a thin air bearing is formed between the surface of the magnetic disk and an air bearing surface (ABS) of the slider. The read and write elements of the head are alternatively used to read and write data while a suspension assembly positions the head along magnetic tracks on the magnetic disk. The magnetic tracks on the magnetic disks are typically concentric circular regions on the magnetic disks, onto which data can be stored by writing to it and retrieved by reading from it.
The slider is aerodynamically designed to fly above a rotating magnetic disk by virtue of an air bearing created between the ABS of the slider and the rotating magnetic disk. The ABS is the portion of the slider surface which is closest to the rotating magnetic disk, which is typically the head portion of the slider. In order to maximize the efficiency of the head, the sensing elements (i.e., the read and write heads) are designed to have precise dimensional relationships to each other. In addition, the distance between the ABS and the rotating magnetic disk is tightly controlled. The dimension that relates to the write function is known as the throat height and the dimension that relates to the read function is known as the stripe height. Both the stripe height and the throat height are controlled by lapping processes.
Multiple lapping processes are performed on row bars, which are rows of sliders/heads, and include backside lapping followed by frontside lapping. During the lapping process, row bars are mounted on a separate lapping tool at each lapping operation using an adhesive, tape and/or separate double-sided adhesive film. The lapping process alters and removes materials, as well as polishes, the row bars, which creates stresses on and within the surfaces of the row bars that are lapped. If these stresses are not released and are left in the finished magnetic head, which is made from a row bar, the stresses can cause the finished magnetic head to be damaged later. Therefore, these stresses are released and corrected during the manufacturing process. The damage occurs because magnetic heads which are stressed are also unstable and can change their shape later after they have been installed in a hard drive. The magnetic head's shape changes because of instability, which results from stress built up. When this change occurs it is referred to as “POPPING” because the change is a permanent over coat protrusion (POP) that occurs on the surface of the head and resembles the magnetic head surface popping up. Therefore, as part of the manufacturing process, the stress built up in the head, which is a result of processes like lapping, is released in order to stabilize the head and avoid “POPPING” later.
Conventional methods of releasing these stresses involve annealing the head at high temperatures to induce the “POPPING” to occur and therefore remove the instability from the magnetic head. The conventional high temperature annealing process, which is used to relieve stresses, is optimally performed just prior to the final lapping operation and after the rough lapping operation. However, using high temperature annealing on row bars of magnetic heads, after rough lapping, requires the row bars to be de-bonded from a lapping row tool because high temperature annealing can destroy the adhesive and mounted wire bond board. These steps of bonding and de-bonding wires to row bars require significant extra processing steps that are expensive.
Therefore, what is needed is a system and method that releases stresses built up in row bars as a result of fabrication processes, such as lapping, as well as reduces the number of times that wires are bonded and de-bonded to row bars and thus lowers magnetic head fabrication costs.